Phase transitions and self-assembly in meso-tetrakis(undecyl)porphyrin

被引：15

作者：

Burrows, HD ^{[1
]}

Gonsalves, AMR ^{[1
]}

Leitao, MLP ^{[1
]}

Miguel, MD ^{[1
]}

Pereira, MM ^{[1
]}

机构：

[1] Univ Coimbra, Dept Quim, P-3049 Coimbra, Portugal

来源：

SUPRAMOLECULAR SCIENCE | 1997年 / 4卷 / 3-4期

关键词：

porphyrins; phase transitions; spectra; thin films;

D O I：

10.1016/S0968-5677(97)00010-2

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The phase behaviour of meso-tetrakis(undecyl)porphyrin, made available in a highly pure form through novel improvements on the porphyrin synthesis (Johnstone, R. A. W., Nunes, M. L. P. G., Pereira, M. M., Rocha Gonsalves, A. M. d'A. and Serra, A. C., Heterocycles, 1996, 43, 1423), was studied to estimate its tendency to self-assemble. Visual observations and differential scanning calorimetry (DSC) studies show the presence of two polymorphic phases between crystal and isotropic liquid. On cooling and reheating different phase behaviour is observed, indicating the formation of a metastable phase from the melt. Infra-red spectral studies suggest that the dominant process on melting involves disordering of the alkyl chains. Films of the porphyrin can be prepared by melting and rapidly cooling, although these are rather brittle. They show modifications in their UV/visible absorption spectra compared with solutions, including slight red shifts and partial splitting of the lowest-energy bands. Fluorescence spectra of the films are also red shifted and split compared with the porphyrin in solution, and show dramatic decreases in fluorescence intensities. The UV/visible absorption and fluorescence results are interpreted in terms of inter-porphyrin interactions, due to stacking. (C) 1997 Elsevier Science Ltd. All rights reserved.

引用

页码：241 / 246

页数：6

共 20 条

[1] PRESENT LIMITS OF DATA-STORAGE USING DYE MOLECULES IN SOLID MATRICES [J].